Efficient hydrodeoxygenation of methyl palmitate over NiMo/ZrO2 catalyst with electron transfer between Ni and Mo

Abstract

The hydrodeoxygenation of biomass into high quality fuels is one of the effective technologies to produce green diesel and solve the environmental pollution of fossil fuels at source. In this work, the catalytic performances of NixMoy/ZrO2 catalysts for methyl palmitate hydrodeoxygenation were evaluated, and the characterization results were combined to understand their role of physicochemical and structural properties in modulating the specific selectivity of alkanes. Under mild reaction condition (270 °C, 3 MPa), the Ni1Mo1/ZrO2 catalyst showed the best hydrodeoxygenation reactivity (conversion: 99.4%) and alkane selectivity (95.0%, hexadecane: 73.6%) of methyl palmitate. It was found that the electron transfer from Mo to Ni in Ni1Mo1/ZrO2 catalyst promoted the active site Ni anchoring and H2 molecules activation, which were associated with the better hydrodeoxygenation activity. In addition, the highest oxygen vacancies and Mo5+ content in Ni1Mo1/ZrO2 catalyst benefited the adsorption and breaking capacity of CO/C-O bonds and hexadecane yield. The Ni1Mo1/ZrO2 catalyst maintained excellent catalytic performance and structural stability after a long-term test of 60 h, which could be efficiently applied for hydrodeoxygenation of methyl palmitate.